Hydrocarbon process



Patented May 19, 1953 UNITED STATES PATENT orrlcc HYDROCARBON PROCESSRobert M. Kennedy, Newtown Square, and Abraham Schneider, Philadelphia,Pa., assignors to Sun Gil Company, Philadelphia, Pa., a corporation ofNew Jersey Application July 14, 1950, Serial No. 173,746

1 23 Claims.

This invention relates to the separation of hydrocarbons according tochemical type, and more specifically to a process for the separation ofaromatic hydrocarbons from saturated nonaromatic hydrocarbons.

The separation of aromatic hydrocarbons from non-aromatic hydrocarbons,or an adjustment of the relative concentrations in a mixture thereof, isessential in order to prepare oils for special uses, such as electricaland lubricating oils. Methods heretofore used include, for example,treatment with solid contact material such as silica gel, or relatedabsorbents. Such processes, however, are subject to certaindisadvantages, including the difficulty in separating only a givenquantity of aromatics to obtain a product hav ing a predeterminedaromatic concentration, and the difiiculty of substantially completelyseparating aromatics when desired. Deactivation of the absorbent and thesimultaneous separation of desired non-aromatic hydrocarbons, togetherwith the aromatics, illustrate further diflioulties of prior processes.Another process whichhas been described as useful in removing aromaticsfrom non-aromatics is the contacting of a mixture thereof with hydrogenfluoride and boron fluoride. This process also suff-ersiromdisadvantages, such as the necessity for vigorous agitation to obtainmixing of the two phase system, and relatively large quantities ofhydrogen fluoride are required to remove a substantial quantity ofaromatics.

An object of the present invention is to provide a process for theremoval of a desired quantity of aromatics from a mixture ofhydrocarbons whereby a predetermined concentration of arcmatics ispermitted to remain in the resulting product. A further object is toprovide'a process for the removal of substantially all of the arc--matics from a hydrocarbon mixture containing aromatic hydrocarbons andsaturated non-aromatc hydrocarbons. Other objects appear hereinafter.

In copending application Serial No. 173,747, filed July 14, 1950, thereis described and claimed a process for the separation ofnon-hydrocarbons from hydrocarbons which comprises bringing togetherboron fluoride and a tertiary alkyl fluoride in the presence of amixture of non-hydrocarbons and hydrocarbons, whereby a sludge con--taining the non hydrocarbons is formed and separates from the reactionmixture. in this process, if the quantity of alkyl fluoride used is inexcess of the quantity required to remove the non-hydrocarbons,non-alkylatable aromatics are converted to and form a portion of thesludge,

, but only after substantially complete removal of the non-hydrocarbons.

In. patent application Serial No. 173,748, died July 14, 1950, there isdescribed and claimed a process for separating non-alkylatablehydrocarbons from saturated non-aromatic hydrocarbons by bringingtogether boron fluoride and a tertiary alkyl fluoride in the presence ofa mixture thereof, whereby the non-alkylatable aromatics are convertedto and separate as a sludge.

In patent application Serial No..173,745, filed July 14, 1950, there isdescribed and claimed a process for the separation of non-hydrocarbonsfrom hydrocarbons which comprises bringing together boron fluoride and aprimary or secondary alkyl fluoride in the presence of a mixturethereof, whereby a sludge containing. the non-hydrocarbons is formed. Inthis process, if the quantity of alkyl fluoride used is inexcess of thequantity required to remove the non-hydrocarbons, the aromatics areconverted to and form a portion of the sludge, but only aftersubstantially complete removal of the nonhydrocarbons.

In patent application Serial No. 38,167, filed July 10,.19 l8, nowPatent Number 2,557,113, there is described various reactions or"hydrocarbons having at least one tertiary hydrogen atom per moleculesuch as alkylation, isomerization, and the like, using boron fluorideand an 'alkyl fluoride having at least two carbon atoms per molecule asthe catalytic components to initiate such reactions, the process beingconducted in the absence of aromatics.

In patent application Serial No. 130,926, filed December 3, 194-9, thereis described thealkylation or alkylatable aromaticswith saturatehydrocarbons having at leastfive carbon atoms and one tertiary hydrogenatom per molecule by bringing together a tertiary alkyl fluoride andboron fluoride in the presence of a mixture thereof, the mole ratio oftertiary alkyl' fluoride-to aromatics plus saturates being from 1:20'to3:5, and the mole ratio of saturates to aromatics being from 1:4 to 4:1.

It has now been discovered that by bringing together boron fluoride anda primary alkyl fluoride having at least two carbon atoms per moleculeor a secondary alkyl fluoride in the presence of a mixture'of saturatednon-aromatic hydrocarbons and aromatic hydrocarbons, a catalyticcondition is established which is effective to remove the'aromatics, andthat the amount of aromatics removed is substantially dependent upon theamount of alkyl. fluoride employed.

. The combination of the present catalytic agents, a primary orsecondary alkyl fluoride and boron fluoride, has been found to beextremely potent and highly selective for the removal. of aromatichydrocarbons from an admixture thereof with saturated non-aromatichydrocarbons such as paraffins, including branched chain paraffins, andcycloparaffins, including: naphthenes. Only after substantially completeremoval by sludge formation of aromatics do the reactions described inaforesaid patent application Serial No. 37,167 occur. actions describedin aforesaid patent application Serial No. 130,926 do not occur with'the present combination of refining agents. Thus, by proper adjustmentof operating conditions,particularly the concentration of alkylfluoride, as herein after described, all or a predeterminedproportion ofaromatics may be removed from .a hydcarbon mixture without anysubstantial loss or valuable non-aromatic hydrocarbons by sludgeformation or degradation to undesired coni- Thus, in acc'o'rdar'ice withthe present invention, when boron fiuoride'and a primary 'o'r-secondaryalkyl fluoride havinga't least two carbon atoms per moleculeare broughttogether in the presence of aromatics andsaturatednon aromatics, thearomatics are converted to and separate" an insoluble sludge, theamountof conversion beingv dependent upon the quantity of 'alkylfluoride employed. Since alkyl'ationreactions' do not occur-in thepresent process, both alkylatable and non alkylatable aromatics areconverted without distinction, the expression non-"alkylatable" being.employed to indicate aromatics which are not alkylatable underalkyl'ating iconditions."

A substantial advantage of Tthe"present refining process is thatboth ofthecoinponents of the catalytic combination are soluble "inhydrocarbons, thus eliminating" the necessity for the vigorousagitationin processes involving insoluble --reagents, such as sulfuric acid;hydrogen fluoride and aluminum chloride; "The present reaction mixtureforms a homogeneous phase whereinreaction occurs and on completion ofwhich the system becomes heterogeneous due to the formation of asludgecomposed of undesirable constituents of the hydrocarbons. It ischaracteristic ofthe present'process that. the alkyl fluoride employedin the process isconverted to'the corresponding parrafiin. For example,if isopropyl fluoride is employed," propane isformed therefromand-isaproduct of the reaction. A further advantage of the present process istheinstantaneous natureof thepresentreactiomwhich occurs-and iscompleted practically assoon as-the catalytic components, an alkylfluoride and boron fiuoride,.are' brought togetherin the presence oftheoil being treated. Itfollows-that time -is-not a criticalvariable inthe process, and no advantage isobtained bylong periods of contact.-For-- practical. convenience, a contact time of from 1 to 40 minutesissuitable. Aromaticswhiohoccur. in petroleum and the various fractionsobtainable therefrom, such as the gasoline, kerosene,- and lubricating'oil fractions; may be'removed in part-or in whole in accordance'vviththe: present. process. Normally =so1id petroleum fractions mayalsobetreated,

in which case the temperature is .maintained sufficiently high. to keepthe fraction in the liquid "phase. Unsaturated non-aromatichydrocarbons, 'such as olefins;.should notx-be present in the reactionmixture -to any substantial extent,

andshould constitute not morethan 1% of the hydrocarbon charge.Non-hydrocarbons, i. e.,

The alkylationi re-' '4 organic compounds having as a constituent anelement other than carbon or hydrogen, such as sulfur, oxygen, andnitrogen compounds, should not be present in the reaction mixture, andif initially present should be removed before subjecting the; charge tothe present. process. In general, the non-hydrocarbon content of thecharge should be less than 0.03%, since otherwise the reactions ofaforesaid patent application Serial-No. 173,745 occur.

As above described, the separation. of aromatics-frompetroleum and thefractions and hydrocarbons obtainable therefrom are preferredembodiments of the present process, and the wide variety of aromatics,occurring in petroleum which-are removable illustrates the versatilityof the process. Aromatics occurring in petroleum which are readilyremovable in the present process, for example, include the substitutedaromatics -of the-benzene, naphthalene, tetralin, anthracene, andphenanthrene 1 series, although other aromatics, such as. theunsubstituted ho mologues of the described aromatics, may be removedinthe present processas above described. In general; the'concentration-of aromatics in the oil tobe"t'reated wilbnot exceed-about50% by volumajand usually-iswithin therange of from 1% to 30% by-volumeyconcentrations of less than 1% may-beadvantageously removed inthe present-process when it is desired to substantiallycompletely-remove the aromatics.

33y petroleum hydrocarbons, as used herein, is meant those;-hydrocarbons Which-- can be obtained from -petroleum;- and mixturesthereof; by petroleum--isimeant petroleum which has not been separatedinto--fract-ions, and which therefore contains hydrocarbons havingwidely varying boiling points; and by- -petro1eum fractions,.and;fractiom;is--meant a mixture of hydrocarbons obtained'frompetroleumhaving a relatively narrow boiling; ;range.- Hydrocarbons and mixturesthereof obtainedfrom sources other than petroleum may"be-separ-ated fromaromatics. For example, hydrocarbon mixtures of arcmatics andnon-aromatics obtained from coal tar attached to a;primary or asecondary carbon atom, respectively, Y

As specific examples of primary fluorides which can be .used inpraqticing the process, the following may be mentioned by Way ofillustration: ethyl fluoride IQ-fiuoropropane; 1-fluorobutane;l.-fluoro-.-2-methylpropane; l-fiuoropentane; 1- fiuoro-3-methylbutane;and similar derivatives of hexanes, hep'tanes, 'octanes, and" the like.As specific illustrations, of secondary fluorides, the following canbensed: gisopropyl fluoride; Z-fiuorobutane; 2 -fiuoro-3 methylbutane; 2-fluoropentane; 3 fluoropentane; ,and,,2'- fiuoro 3,3 dimethylbutane. lIt willbc understood that the specific comp u d named leav are g nmerely -by:way ,of..i]lustration ,andthat any primary or secondary alkylfluoride (with the exception of methyl fluoride) will produce anoperative catalytic combination with BFs in accordance with the presentinvention.

In carrying out the process of the present invention, it is preferred tofirst dissolve the desired amount of alkyl fluoride in the oil, and thenadd the BF:;, such as by bubbling it into the solution. It ispermissible, however, to simultaneously but separately introduce therefining agents, or to first dissolve BF: in the oil followed byaddition of the alkyl fluoride. It is also permissible to dissolve thealkyl fluoride and BF; in separate portions of the oil and then admixthe portions, thus bringing together the refining agents in the presenceof the oil. It is not permissible to premix the alkyl fluoride and BFssince, in such case, the catalytic condition required to be exerted inthe presence of the mixture of aromatics and non-aromatics being treatedis immediately dissipated. By the expression bringing together, andterms of similar import, as employed herein in conjunction with the useof the present refining agents, is meant the actual contacting thereof,which in the present process is always performed in the presence of theoil being treated, i. e., the present refining agents, alkyl fluorideand boron fluoride, are contacted only when they are also in contactwith the oil being treated.

As above described, the quantity of aromatics removed is substantiallydependent upon the quantity of alkyl fluoride employed. Accordingly, theconcentration of alkyl fluoride required to obtain the desired reductionof aromatic content should be determined for each application, which canbe readily accomplished in view of the present teachings. For example,it has been found that aromatic content of a petroleum lubricating oilfraction, initially about 23% by vol. ume and composed substantially ofnon-alkylatable aromatics, is reduced about 20% by treatment of thefraction with 1% by weight of tertiary butyl fluoride, and is reducedabout 50% by treatment with 2.3% by weight of the same fluoride, in bothinstances using an excess of boron fluoride, and the separation of suchlarge amounts of aromatics with only small quantities of alkyl fluorideis considered a significant advantage of the present process. Equalmolar quantities of the various alkyl fluorides within the scope of thepresent invention remove sub-' stantially the same quantity of aromaticsfrom a given mixture. In general, from 0.5 to 20 weight percent of alkylfluoride will be employed, although in some instances such as where itis desired to remove a large quantity of aromatics, as much as 30 weightpercent may be used, so long as the amount used is not in excess of theamount required to remove all of the aromatics.

As above stated, the concentration of boron fluoride to employ is notcritical, the requirement being that a quantity sufficient to establishthe necessary catalytic condition be employed. In general, from 0.1 to400 weight percent, and preferably from 0.3 to 200 weight percent, basedon the weight of alkyl fluoride employed, is suflicient to causecompletion of the present process to the desired extent, which, as abovedescribed, is substantially determined by I the quantity of the alkylfluoride employed.

The present reaction is conducted in the liquid phase. Super-atmosphericpressure is preferred so that the desired amount of boronfluoridereadily dissolves in the reaction mixture.

Pressures of from atmospheric to 500 p. s. i., d

8 pending on the concentration of boron fluoride desired, is suitable inmost instances.

The operable temperature range varies considerably and depends largelyon the particular material being treated. A temperature sulficientlyhigh to maintain the hydrocarbons in a fluid, i. e., non-viscous, stateis preferred. In general, temperatures of from 20 C. to C. are employed.If it is desired to operate at lower temperatures the lowest temperatureat which the secondary fluoridesv can be employed is 90 C. and thelowest temperature at which primary fluorides can be employed is 10 C.An exception is ethyl fluoride, which has been found to be somewhat moreinert than the alkyl fluorides having 3 or more carbon atoms permolecule, and which requires a temperature of above about 20 C. to beoperable in the present process.

As above described, the refining agents are soluble in the present oils,and on completion of the reaction, which is practically instantaneous, asludge separates to form a heterogeneous phase. As already described,only insignificant amounts of non-aromatic hydrocarbons are converted tosludge. The sludge may be separated by any convenient or desired means,such as by filtering, centrifuging, or decanting. The oil, after sludgeremoval, is advantageously washed with water or an aqueous solution ofan alkali, such as sodium hydroxide, or it may be treated with ammonia.The refined product is obtained by separating the heterogeneous phase ofthis last treatment, and is preferably dried if necessary or desirable.Treatment of the oil with clay, such as is usually required aftersulfuric acid refining, is not required, but of course may be employedif desired, as may other process steps known to the art.

Boron fluoride and hydrogen'fluoride are easily recoverable from theseparated sludge by heating or applying a vacuum, or both. For example,heating to about C. under slight vacuum drives on hydrogen fluoride andboron fluoride, which may be recovered, the boron fluoride beingre-cycled to the system and the hydrogen fluoride being used to prepareadditional alkyl fluoride, such as by addition reaction with anappropriate olefin, as known to the art, the resulting alkyl fluoridebeing then employed in the process. The product remaining after removalof the boron fluoride and hydrogen fluoride may be employed as fuel or.as a componen't of compositions useful, for example, in paving roads andthe like.

Attention is now directed to the accompanying flow diagram whichillustrates an embodiment of the present invention, and is directed tothe separation of aromatic hydrocarbons from saturated non-aromatichydrocarbons con tained in a saturate petroleum fraction. The mixture ofhydrocarbons to be treated, such as a petroleum lubricating oilfraction, is introduced into the process through line I and isopropylfluoride, used to illustrate the various alkyl fluorides which may beemployed, is introduced into the system through line 2. A mixture of thepetroleum fraction and isopropyl fluoride passes through line 3 intoheat exchanger 4 wherein the temperature of the mixture is adjusted tothe desired value, usually from 20 C. to'150 C. The mixture then passesthrough line 5 into mixer 6, into which the BF; is introduced throughline 8. Means to provide mild agitation in mixer 6 may be' suppliedifdesiredbut may be omitted if the turbulence of flow is Sui-1 flcient-:to secure substantially uniform mixing. On introduction .of EtherBFs,reaction be ins and proceeds rapidly :to completion with formation of 1asludge composed ilargely .of aromatic 1components of :the petroleum-;fraction. The sl d econtaining fr-action passes -through {line -9 intoseparator .10, sludge abQi-ll removed therefrom through line H and t11refinediracti0 thr u line 1 2. Propane formed from the isopropylfluoride is removed from the separator through line IS. The refinedinaction passes into tower :Hl wherein it is treated to remove anyentrained acid gases such as by washing with water, the .water beingintroduced into tower it through line ;l: 5. Refined product is removedthrough iii and the =,use d water through line =18. 'The refined productmay be dried and further treated as desired. :Sludge from separator Hlpasses through line fl into distillation zone I19, and Bi s and areevolved therefrom. 335% is re- .cyoled to the process through lines 2i)and 8.

passes through line 2;! into reactor 22 Wherein it is reacted withpropylene supplied through line 24 to form isopropyl fluoride, which isintroduced into the process through lines 25 and -2. Residue from .di;s,tillation zone i9 is removed through line 26 and may be employed asfuel or as a component of compositions useful, for ex ampl in pavin roas he l k The quantity of reactants to employ and the various operatingconditons are advantageously maintained as heroinbefore described:

The following example illustrates the process of the present invention:

A light kerosene fraction wa treated with silica. gel to remove aportion of the aromatics and substa-ntiaily all of the non-hydrocarbons.One hundred parts by weight of the treated. fraction containing 1 volumeper cent aromatics were admixed with v2.5 parts by weight of t-butylfluoride. Nine parts by weight of boron fluoride were added; thepressure was 120 p. s. i. and the temperature 23 6. small amount ofsludge, about 4 parts by Weight, formed and was separated by decanting.The quantity of aromatic remaining the product was less than 0.2 volumepercent. The product exhibited improved color, color stability, andanti-sludging properties.

When a primary or secondary alkyl fluoride having at least 2 carbonatoms per molecule is employed in place of t-butyl fluoride, results substantially identical thereto are obtained.

Modifications in the described procedure will be apparent to thoseskilled in th art; the presout process may be adapted to batch orcontinuous operation.

The separation of non-hydrocarbons, either alone or together witharomatics is not within the scope of the present claims, but is claimedin aforesaid patent application Serial No. 173,745, filed July 14, 1950.

The invention claimed is:

1. Process of treating hydrocarbons to separate aromatic hydrocarbonsfrom a mixture thereof with saturated non-aromatic hydrocarbons whichoomprises reacting a mixture of aromatic hydrocarbons and saturatednon-aromatic hydrocarbons with boron fluoride and an alkyl monofluorideselected from the group consisting of primary alkyl mono-fluorideshaving at least two carbon atoms per molecule and secondary alkylmono-fluorides as the sole refining agents, said boron fluoride and saidal-k-yl mono fluoride beiiig brought together only in the presence ofsaid mixture of aromatic hydrocarbons and saturated .non aromatichydrocarbons, whereby aromatic hydrocarbons are converted to a sludge,and separating said sludge from the reaction mixture.

2. Process for separating aromatic hydrocarbons from a petroluemfraction containing the same and saturated non-aromatic hydrocarbonswhich comprises reacting a petroleum fraction containing aromatichydrocarbons with boron fluoride and an alkyl mono-fluoride selectedfrom the group consisting of primary alkyl monofluorides having at leasttwo carbon atoms per molecule and secondary alkyl mono-fluorides as thesole refining agents, said boron fluoride and said alkyl mono-fluoridebeing brought together only in the presence of said petroleum fraction,whereby aromatic hydrocarbons are converted to an insoluble sludge, andwherein the quality of alkyl mono-fluoride employed is not in excess ofthe amount required to convert all of said aromatic hydrocarbons tosludge, and separating said sludge from the reaction mixture.

Process according to claim 2 wherein the alkyl fluoride is a primaryalkyl fluoride having at least two carbon atoms per molecule.

4. Process according to claim 2 wherein allryl fluoride is1-fluoro-3-methylbutane.

5. Process according to claim 2 wherein alkyl fluoride is a secondaryalkyl fluoride.

6. Process according to claim 2 wherein alkyl fluoride is isopropylfluoride.

'7. Process according to claim alkyl fluoride is Z-fluorobutane.

8. Process according to claim alkyl fluorid is 2-fluoropentane.

9. Process according to claim 2 wherein alkyl fluoride is2-fluoro-3,3-dimethylbutane.

10. Process for separating aromatic hydrocarbons from a lubricating oilfraction comprising aromatic hydrocarbons and saturated non-aromatichydrocarbons which comprises reacting said lubricating oil fraction withboron fluoride and an alkyl mono-fluoride selected from the groupconsisting of primary alltyl mono-fluorides having at least two carbonatoms per molecule and secondary alkyl mono-fluorides as the solerefining agents, said boron fluoride and said alkyl mono-fluoride beingbrought together only in the presence of said lubricating oil fraction,and wherein the quantity of alkyl mono-fluoride employed is not inexcess of the amount required to convert all of said aromatichydrocarbons to sludge, and separating said sludge from the reactionmixture.

11. Process according to claim 10 wherein the alkyl fluoride is aprimary alkyl fluoride.

12. Process according to claim 10 wherein the alkyl fluoride is a.secondary alkyl fluoride.

13. Process according to claim 10 wherein the alkyl fluoride isisopropyl. fluoride.

14. Process for separating aromatic hydrocarbone from a kerosenefraction comprising aromatic hydrocarbons and saturated nonaromatichydrocarbons which comprises reacting said kerosene fraction with boronfluoride and an alkyl mono-fluoride selected from. the group consistingof primary alk-yl mono-fluorides having at least two carbon atoms permolecule and secondary alkyl mono-fluorides as the sole refining agents,said boron fluoride and said alkyl, mono-fluoride being brought togetheronly in the presence of said kerosene traction, and wherein the quantityof alkyl mono-fluoride employed is not in excess of the, amount:required to; convert all of said aromatic hydrocarbons to sludge, andseparating said sludge from. the reaction mixture.-

the

the

the

2 wherein the 2 wherein the the 15. Process according to claim 14wherein the alkyl fluoride is a primary alkyl fluoride.

16. Process according to claim 14 wherein the alkyl fluoride isisopropyl fluoride.

17. Process according to claim 14 wherein the alkyl fluoride is asecondary alkyl fluoride.

18. Process for separating aromatic hydrocarbons from a gasolinefraction comprising aromatic hydrocarbons and saturated non-aromatichydrocarbons which comprises reacting said gasoline fraction with boronfluoride and an alkyl mono-fluoride selected from the group consistingof primary alkyl mono-fluorides having at least two carbon atoms permolecule and secondary alkyl mono-fluorides as the sole refining agents,said boron fluoride and said alkyl monofluoride being brought togetheronly in the presence of said gasoline fraction, and wherein the quantityof alkyl mono-fluoride employed is not in excess of the amount requiredto convert all of said aromatic hydrocarbons to sludge, and separatingsaid sludge from the reaction mixture.

19. Process according to claim 18 wherein the alky1 fluoride is aprimary alkyl fluoride.

20. Process according to claim 18 wherein the alkyl fluoride is asecondary alkyl fluoride.

21. Process according to claim 18 wherein the alkyl fluoride isisopropyl fluoride.

22. Process of treating a mixture of aromatic and non-aromatichydrocarbons to obtain a product having a predetermined concentration ofaromatic hydrocarbons less than the concentration thereof in saidmixture which comprises reacting said mixture of aromatic and saturatednon-aromatic hydrocarbons with boron fluoride and a predeterminedquantity of an alkyl monofluoride selected from the group consisting ofprimary alkyl mono-fluorides having at least two carbon atoms permolecule and secondary alkyl mono-fluorides as the sole treating agents,said iii boron fluoride and said alkyl mono-fluoride being broughttogether only in the presence of said mixture of aromatic and saturatednon-aromatic hydrocarbons, whereby a portion of said aromatichydrocarbons is converted to an insoluble sludge, and separating amixture of aromatic and saturated non-aromatic hydrocarbons having apredetermined concentration of aromatic hydrocarbons from the reactionmixture.

23. Process for separating aromatic hydrocarbons from a lubricating oilfraction comprising aromatic hydrocarbons and saturated non-aromatichydrocarbons which comprises reacting said fraction with boron fluorideand isopropyl fluoride as the sole refining agents, said boron fluorideand said isopropyl fluoride being brought together only in the presenceof said fraction, whereby aromatic hydrocarbons are converted to aninsoluble sludge and said isopropyl fluoride is converted to propane,and wherein the quantity of isopropyl fluoride employed is not in excessof the amount required to convert all of said aromatic hydrocarbons tosludge, and separating sludge and propane from the reaction mixture.

ROBERT M. KENNEDY.

ABRAHAM SCHNEIDER.

References Cited in the file of this patent -UNITED STATES PATENTSNumber Name Date 2,162,682 Terres June 13, 1939 2,267,730 Grosse et a lDec. 30, 1941 2,343,744 Burk Mar. 7, 1944 2,343,841 Burk Mar. 7, 19442,357,495 Bloch Sept. 5, 1944 2,378,762 Frey "a June 19, 1945 2,408,173Matuszak Sept. 24, 1946 2,472,908 Linn June 14, 1949 2,507,599 Cade May16. 1950

1. PROCESS OF TREATING HYDROCARBONS TO SEPARATE AROMATIC HYDROCARBONSFROM A MIXTURE THEREOF WITH SATURATED NON-AROMATIC HYDROCARBONS WHICHCOMPRISES REACTING A MIXTURE OF AROMATIC HYDROCARBONS AND SATURATEDNON-AROMATIC HYDROCARBONS WITH BORON FLUORIDE AND AN ALKYL MONOFLUORIDESELECTED FROM THE GROUP CONSISTING OF PRIMARY ALKYL MONO-FLUORIDESHAVING AT LEAST TWO CARBON ATOMS PER MOLECULE AND SECONDARY ALKYLMONO-FLUORIDES AS THE SOLE REFINING AGENTS, SAID BORON FLUORIDE AND SAIDALKYL MONO-FLUORIDE BEING BROUGHT TOGETHER ONLY IN THE PRESENCE OF SAIDMIXTURE OF AROMATIC HYDROCARBONS AND SATURATED NON-AROMATICHYDROCARBONS, WHEREBY AROMATIC HYDROCARBONS ARE CONVERTED TO A SLUDGE,AND SEPARATING SAID SLUDGE FROM THE REACTION MIXTURE.